Now, before I say anything else, take this information with a grain of salt. While it originated from a good source, it was a second-hand source. Meanwhile, I’ve corroborated some the main details with another source, but not some of the smaller ones. That said, from what I’m hearing, Apple is pretty far along on work on second tablet device. A bigger one. And this one may be much more like a Mac than an iPhone.

Specifically, TC’s source notes that Apple may be working on a tablet with a 15.4-inch screen, which would put it on par with the current MacBook Pro screen. This supposed tablet would also “run a version of OS X much closer to the traditional version that runs on Macs.”

This isn’t the first we’ve heard of a ginormous tablet device being developed deep beneath the bowels of 1 Infinite Loop. Back in August, reports surfaced that Apple was not only working on a 10-inch tablet, but that it was also toying with 13 and 15 inch form factors as well, with the larger one apparently running a full version of OS X.

Now before you go jumping to conclusions, keep in mind that in developing the iPad, Apple reportedly experimented with a broad range of tablet sizes, and so while a larger tablet device may indeed be floating around Apple’s labs, it’s still far too early to start discussing an even larger version of the iPad.

Besides, given the way Apple tpyically does business, it’s going to wait and see how successful the iPad is before it even considers an entirely new form factor.